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Home My WebLink About20230271 Ver 1_Design/Maps/Site Plans Revised_20240202Freshwater Mussel Survey Report Walker Branch/Hoover Creek Site Steele Creek Sub -Watershed Mecklenburg County, North Carolina Habitat in Walker Branch -Reach 1 Prepared For: Hazen July 26, 2023 Prepared by: 324 Blackwell Street, Suite 1200 Durham, NC 27701 Contact: Tim Savidge tim.savidge@threeoaksengineering.com 919-732-1300 TABLE OF CONTENTS 1.0 INTRODUCTION............................................................................................................2 2.0 SURVEY EFFORTS........................................................................................................2 2.1 Methodology.................................................................................................................2 3.0 RESULTS........................................................................................................................3 3.1 Reach 1 - Walker Branch..............................................................................................3 3.2 Reach 2 - Walker Branch..............................................................................................4 3.3 Reach 3 - Hoover Creek................................................................................................4 3.4 Reach 4 - Hoover Creek................................................................................................5 4.0 CONCLUSIONS..............................................................................................................5 APPENDIXA. Figures...............................................................................................................6 APPENDIX B. Select Photographs...........................................................................................12 1.0 INTRODUCTION Mecklenburg County is proposing a greenway project that involves dewatering of Walker Branch/Hoover Creek to install bridge abutments and protection, stream enhancement, and temporary stream crossings. There are a total of five in -stream impact areas, three in Walker Branch and two in Hoover Creek. The state endangered Carolina Creekshell (Sagittunio vaughanianus) has been recorded in the vicinity of the subject project. Based on correspondence from the North Carolina Wildlife Resources Commission (NCWRC), surveys for freshwater mussels were recommended to occur within each of the five in -stream project footprints, plus buffers extending 50 meters (m) upstream and 100 m downstream respectively. In addition, if any Carolina Creekshell individuals were found, they were to be removed from the stream and taken to the NCWRC mussel hatchery in Marion, North Carolina. Three Oaks was retained to conduct these surveys and coordinate with NCWRC if the Carolina Creekshell was found during these efforts. Completion of these surveys was specified as a condition of the Section 401 of the Clean Water Act Authorization. Three Oaks Engineering (Three Oaks) was retained by Hazen & Sawyer on behalf of Mecklenburg County to conduct these surveys. 2.0 SURVEY EFFORTS Mussel surveys were conducted within the Project streams by Three Oaks personnel Tim Savidge (Permit # 23-ES0034) on July 12, 2023, and Tim Savidge and Zach Biltoft on July 13, 2023. All five impact areas within the project site were surveyed for the recommended survey lengths. The two impact sites located in the upper portion of Walker Branch were in close proximity to each other of the impact, with overlapping buffers. This resulted in four distinct stream reaches (Reaches 1-4) being surveyed (Figure 1, Appendix A). Mussel surveys targeting the Carolina Creekshell were conducted in a total of 340 m of Walker Branch and 300 m of Hoover Creek. 2.1 Methodology Visual surveys for mussels were conducted in the surveyed stream reaches using glass bottom view buckets (bathyscopes). Tactile methods were employed, particularly in streambanks under submerged rootmats. All areas of appropriate habitat were searched, concentrating on the stable habitats preferred by the target species. The survey team spread out across the creek into survey lanes. If encountered, all freshwater bivalves were to be recorded and returned to the substrate. The efforts were timed to provide Catch Per Unit Effort (CPUE) data for each species found. Relative abundance for freshwater snail and clam species were estimated using the following criteria: Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 2 ➢ (VA) Very abundant > 30 per square meter ➢ (A) Abundant 16-30 per square meter ➢ (C) Common 6-15 per square meter ➢ (U) Uncommon 3-5 per square meter ➢ (R) Rare 1-2 per square meter ➢ (P-) Ancillary adjective "Patchy" indicates an uneven distribution of the species within the sampled site. 3.0 RESULTS The Carolina Creekshell was not found during the survey efforts. One freshwater mussel species, the Eastern Elliptio (Elliptio complanata) was found in all of the survey reaches, with the exception of Survey Reach 3. The survey results and brief habitat descriptions of the four evaluated reaches are provided below. 3.1 Reach 1- Walker Branch This reach, depicted in Appendix A, Figure 1-1, encompassed two in -stream impact areas. The surveys began late afternoon of July 12th but were suspended due to diminishing light levels and were resumed on the morning of July I P. The channel ranged from six to 10 feet wide with sandy clay banks two to three feet high that were slightly to moderately eroded. Instream habitat consisted largely of slow flowing runs, with limited pool and riffle habitats. Two dominant substrate types were present within the reach: sand/pebble and saprolite. Small amounts of gravel and/or cobble were also present. The mussels found were almost exclusively restricted to the sand/pebble dominated areas. Surveys were conducted for 2.05 person hours (phr) during which one mussel species was found. Multiple size (=age) classes were present, including young individuals, indicating recent reproduction and recruitment. Two clam species were also found, a native Fingernail Clam (Family Sphaeriidae), which was common throughout the reach and the invasive Asian Clam, which was represented only by two relict shells. (Table 1). Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 3 Table 1. Reach 1-Walker Branch Survey Results Scientific Name Common Name Number CPUE (#/hr) Freshwater Mussels Elliptio complanata Eastern Elliptio 42 20.49/hr Freshwater Snails and Clams Relative Abundance Corbicula fluminea Asian Clam — Shell Material Sphaeriidae A Fingernail Clam C 3.2 Reach 2 - Walker Branch Reach 2 is located just upstream of the Tryon Road crossing of Walker Branch (Appendix A, Figure 1-2). The channel ranged from 15 to 20 feet wide, with moderately eroded banks six to eight feet high. In -stream habitat is characterized by a series of riffle/run/pool sequences. The substrate was dominated by bedrock/boulders, cobble, gravel, and sand. Surveys were conducted for 1.73 phr, with the Eastern Elliptio being found. However, unlike the more upstream Reach 1, the majority of individuals found were older (larger) individuals, with little evidence of recent recruitment. Other mollusk species found include the Asian Clam and a Fingernail Clam (Table 2). Table 2. Reach 2-Walker Branch Survey Results Scientific Name Common Name Number CPUE (#/hr) Freshwater Mussels Elliptio complanata Eastern Elliptio 53 30.64/hr Freshwater Snails and Clams Relative Abundance Corbicula fluminea Asian Clam — P-C Sphaeriidae A Fingernail Clam U 3.3 Reach 3 - Hoover Creek Reach 3 extended from the confluence with Hoover Branch to a point approximately 150 in (492 feet) upstream (Appendix A, Figure 1-3). Near the confluence with Hoover Branch, the channel ranged from 18 to 24 feet wide, with actively eroding banks up to 10 feet high. The channel gradually narrowed to approximately 14 feet wide toward the upstream limits of the reach, with banks approximately eight feet high that have been stabilized by rip rap. The substrate was dominated by sand, gravel, and clay, with a few large boulders also present in the upper portion of the reach. Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 4 Surveys were conducted for 0.87 phr, with the Eastern Elliptio being found in relatively low numbers in two small (10 feet x 3 feet) pockets of gravel substrate along clay banks. While numbers were low, there were at least four size classes observed, including one relatively young (three to four years old) individual. The Asian Clam was also found (Table 3). Table 3. Reach 3-Hoover Creek Survey Results Scientific Name Common Name Number CPUE (#/hr) Freshwater Mussels Elliptio complanata Eastern Elliptio 10 11.49/hr Freshwater Snails and Clams Relative Abundance Corbicula fluminea Asian Clam — P-C 3.4 Reach 4 - Hoover Creek The channel in Reach 4 (Appendix A, Figure 1-4) ranged from 15 to 18 feet wide, with highly eroded banks up to 14 feet high, although the wetted width ranged from five to 10 feet wide during the site visit. Numerous pipes draining adjacent parking lots discharge into this reach. The substrate consisted of unconsolidated sand/pebble, with scattered boulders and occasional pockets of cobble. Surveys were conducted for 0.47 phr and no freshwater mussels were found. The Asian Clam was the only mollusk species found in the reach (Table 4). Table 4. Reach 4-Hoover Creek Survey Results Scientific Name Common Name Number CPUE (#/hr) Freshwater Mussels None Freshwater Snails and Clams Relative Abundance Corbicula fluminea Asian Clam P-U 4.0 CONCLUSIONS The Carolina Creekshell was not found during the survey efforts. One freshwater mussel species, the Eastern Elliptio, was found at three of the four surveyed reaches. While the Carolina Creekshell was not observed, it is possible it is still present in low numbers; particularly in Reach 1, where multiple age classes of the Eastern Elliptio were observed indicating habitat is also likely still suitable for the Carolina Creekshell. The completion of these surveys fulfills the survey requirement condition of the 401 Authorization. The results of these surveys were shared with NCWRC. Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 5 APPENDIX A Figures Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 6 —Z, —444.. .p`; ` jr k lit h :::,._ A� ` ✓5 �, ,ram �i ;�, .,r � c y� rt�' ' ! _ _ '" - �i / 4 Reach 2 ' 17 :' sr' �"�.. d ''�.' � A+1•k Bar,.. _ t Reach 4 Prepared For " , HAZENAND SAWYER I � Environ mentak EnAineeis L Sclenils Fs Reach 3 Freshwater Mussel Survey Walker Branch/Hoover Creek Survey Reaches Mecklenburg County, North Carolina Survey Reach Streams r Roads Date July 2023 Scale. 0 1 300 600 Feet � 1 Jed No 23-327 Drawn BUMS Kt Checked By. TWS Figure Prepared For " , HAZENAND SAWYER I � Environ mentak EnAineeis L Sclenils Fs Freshwater Mussel Survey Walker Branch/Hoover Creek Survey Reach 1 Mecklenburg County, North Carolina Date July 2023 Scale. 0 25 50 Feet 1 1 Jed No 23-327 Drawn CtMS K Checked By. TWS Figure 1-1 Prepared For " , HAZENAND SAWYER I � Environ mentak EnAineeis L Sclenils Fs Freshwater Mussel Survey Walker Branch/Hoover Creek Survey Reach 3 Mecklenburg County, North Carolina Date July 2023 Scale. 0 25 50 Feet 1 1 Jed No 23-327 Drawn CtMS K Checked By. TWS Figure 1-3 Prepared For " , HAZENAND SAWYER I � Environ mentak EnAineeis L Sclenils Fs Freshwater Mussel Survey Walker Branch/Hoover Creek Survey Reach 3 Mecklenburg County, North Carolina Date July 2023 Scale. 0 25 50 Feet 1 1 Jed No 23-327 Drawn CtMS K Checked By. TWS Figure 1-4 APPENDIX B Select Photographs Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 12 it �: � r �`_ r��4A �� 4• �� . �• �y t � .`� r .�.r. yet' '`' x- dt- n rl7 • Photo 1. Assortment of Eastern Elliptio individuals found in Reach 1 Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 13 Pi .. -.^i•- i � -' ..L.•`' ._ y:::�q a- r�ti: �-9 `.T: pa _� - _e•: .�.ti..: � ja,, .._. A„r-s�. • s:i �s�r3 'S i r i�� , s •'... � ,r. �-'4'I�l�''ti � t.'� �,�14�. r� '��F'ryR'i .'�� r'va_�'•+' y'� �r-++.�! ;'f_ r• � 3.. � - .`<+ � � ! - .�. �-'i'" -�.^ y,,.. .. a Photo 3. Large Boulders in upstream extent of Reach 3 Walker Branch/Hoover Creek Mussel Surveys July 2023 Three Oaks Project 23-327 15